THE coldest place in the universe marks the grave of two stars. So says a team that trained the ALMA telescope on the spot, known as the Boomerang Nebula. Point a telescope almost anywhere in the cosmos and you'll see that it is at 2.7 kelvin-cold enough to freeze hydrogen on Earth. But one spot is even colder- the Boomerang Nebula, 5000 light years away in the constellation Centaurus. Here the temperature is 0.1 kelvin, or just above absolute zero. A mystery for years, astronomers can now see that this cosmic winter was caused by a stellar duo's violent death.
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